Condition of British Ebola Patient Worsens

LONDON — A British health worker who is being treated for Ebola in a London hospital is now in critical condition, her doctors said on Saturday.

The patient, Pauline Cafferkey, a nurse from Scotland who had volunteered with the charity Save the Children to care for Ebola victims in Sierra Leone, returned to Glasgow, Scotland, last Sunday. She was hospitalized with a fever and given an Ebola diagnosis on Monday, then transferred to an isolation unit at the Royal Free Hospital in London.

Initial reports suggested that Ms. Cafferkey’s condition was stable, but the hospital said in a statement released Saturday that it was “sorry to announce that the condition of Pauline Cafferkey has gradually deteriorated over the past two days.”

The case of Ms. Cafferkey, who had flown via Casablanca, Morocco, and London Heathrow Airport to Glasgow, has raised questions about the effectiveness of the Ebola screening at Heathrow, a global air hub. The nurse had told officials at the airport that she believed she was developing a fever, and her temperature was taken seven times over a short period, the BBC reported. But when it was normal, she was allowed to continue her travel.

All passengers and crew members who were on the British Airways flight from Heathrow to Glasgow with Ms. Cafferkey have been contacted and given health advice, said a spokeswoman for Health Protection Scotland, which oversees infectious diseases and environmental hazards. All British-based passengers and crew members on the Royal Air Maroc flight from Casablanca to London have also been contacted, the BBC reported. International passengers on that flight are being traced by international authorities, it said.

Ms. Cafferkey, whose infection is the second known case of Ebola in Britain, is being treated with an experimental antiviral drug and blood from Ebola survivors. The previous patient, William Pooley, also a nurse, recovered. He had been treated in the same hospital with another experimental drug, ZMapp, that has also shown promise in treating some patients. But there is a global shortage of ZMapp, and none was available for Ms. Cafferkey.

News of her deteriorating condition came as a South Korean health worker who had come into contact with an Ebola victim in Sierra Leone five days ago was reportedly being monitored at a Berlin hospital for symptoms. No details about the Korean’s identity have been released. Since an Ebola outbreak began in West Africa a year ago, there have been almost 20,000 cases and more than 7,800 deaths, mostly in Liberia, Guinea and Sierra Leone.

Alison Smale contributed reporting from Berlin.

A version of this article appears in print on , on Page A8 of the New York edition with the headline: Condition of British Ebola Patient Worsens. Order Reprints | Today’s Paper | Subscribe